In recent years, proposed are video equipment and audio equipment such as video recorders, audio recorders, television receivers, tuners for receiving various broadcastings and audio amplifiers (referred to as AV equipment or AV devices hereinafter) to be connected to any form of network, such that video data and audio data are transmitted between the interconnected AV devices for sending or receiving data between such devices. Such networking is increasing practicable.
For example, developed are AV devices capable of transmitting data through a network using the IEEE (The Institute of Electrical and Electronics Engineers) 1394 serial data bus. In such network, contents data such as video data and audio data can be transmitted as stream data, and the use of a predetermined command (AV/C Command Transaction Set which is referred to as AV/C commands hereinafter) makes it possible to control the AV devices connected to such network.
In order to transmit the contents data over the designated network, relatively complicated transmission management was required, because it is necessary to acquire channel and bandwidth of the transmission path, to perform plug management for setting the data output and input plugs of each device, and to control transfer contents using the plugs set by such management. As a general purpose network capable of connecting electronic apparatus such as computers, so-called IP protocol configurable networks (such networks using the IP protocol are referred to as IP networks hereinafter) are widely used, but conventionally, it was difficult to control the transfer processing of contents from one AV device to another AV device. In particular, in case of the network using IP protocol, there are various usable protocols, and it was therefore necessary for the user to match the protocol and the like in advance between the sending device and the receiving device. The situation was the same in case of transmitting (or transferring) contents using general purpose networks other than the IP network.